A document from Japan (PATENT ABSTRACTS OF JAPAN, vol. 8, No. 49 (E-230) [1486], 6th Mar. 1984; & JP-A 58 202 581 NIPPON DENSHIN DENWA KOSHA, 25th Nov. 1983) describes a known laser of this kind. In this laser, two top electrodes follow each other over a light guide. One injects a power supply current through an amplifier forming a section of the guide. This current passes through a semiconductor junction in which the guide is inserted. This current thus injects carriers of opposite conductivity type into the guide, which enables the amplifier to effect the amplification needed to build up a light oscillation. The other top electrode injects an absorbance control current into a saturable absorber which is formed by another section of the guide. This current controls the absorbance of the absorber. The absorber is followed by a passive guide.
Other applications of some of the concepts underlying the present invention are disclosed in the commonly assigned U.S. patent application of J. Chesnoy et al. entitled POSITIVE FEEDBACK DEVICE FOR PROCESSING AN OPTICAL SINGAL, filed concurrently herewith under Ser. No. 07/841,710. To the extent such copending application may contain any additional information that might be of any assistance in the use and understanding of the invention claimed herein, It is hereby incorporated by reference.